[mythtv-users] how to adjust commercial notify display time?

I'd like to adjust the length of time a notification of a commercial remains
displayed.
I'm using "notify, but do not skip".
Although there are settings to adjust many similar features, I can't find
anything specifically for length of time displayed.
There is a setting, "commercial skip notify amount", but it changes the time
before a commercial that the notification is presented.
None of the OSD time settings in TV Settings, Playback adjust it either.
Anyone know if such a setting exists?